Selectively doped heterostructure frequency dividers
Abstract
The operation of high-speed divide-by-two circuit (binary counter) composed of selectively doped heterostructure logic gates is reported for the first time. These field-effect transistor circuits utilize the enhanced transport properties of high-mobility electrons confined near a heterojunction interface in a selectively doped AlGaAs/GaAs structure. The dividers are based on a Type-D flip-flop composed of six direct-coupled NOR-gates having 1-micron gate lengths and 4-micron source-drain spacings. They are fabricated by conventional optical contact lithography on a four-layer Al(0.3)Ga(0.7)As/GaAs structure grown by molecular-beam epitaxy. Successful operation is demonstrated at 5.9 GHz at 77 K for 1.3-V bias and 30-mW total power dissipation (including output buffers) and 3.7 GHz at 300 K for 1.4-V bias and 19-mW total power dissipation. Total power dissipation values as low as 3.9 mW at 0.65-V bias were also obtained for 2.85-GHz operation at 300 K. These preliminary results illustrate the promise of SDHT logic for ultrahigh-speed low-power applications.
- Publication:
-
IEEE Electron Device Letters
- Pub Date:
- October 1983
- DOI:
- 10.1109/EDL.1983.25770
- Bibcode:
- 1983IEDL....4..377K
- Keywords:
-
- Aluminum Gallium Arsenides;
- Doped Crystals;
- Field Effect Transistors;
- Frequency Dividers;
- Gallium Arsenides;
- Heterojunction Devices;
- Additives;
- Flip-Flops;
- Lithography;
- Molecular Beam Epitaxy;
- Oscillographs;
- Transport Properties;
- Electronics and Electrical Engineering